遗传性脊髓小脑性共济失调7型的基因突变及临床特征分析  

Analysis of the gene mutation and clinical characteristic of hereditary spinocerebellar ataxia type 7

作　　者：黄智恒[1] 徐评议[1] 梁秀龄[1] 

机构地区：[1]中山医科大学附属第一医院神经科,510080

出　　处：《临床神经病学杂志》2001年第5期272-275,共4页Journal of Clinical Neurology

基　　金：卫生部临床学科重点项目 ( 5 0 )

摘　　要：目的　研究遗传性脊髓小脑性共济失调 7型 (SCA7)的基因突变和临床特征。方法　对临床诊断为脊髓小脑性共济失调 (SCA)的 15个家系 2 4例患者、2 0例散发 SCA患者、41名家系“正常人”及 30名非家系健康人 ,通过聚合酶链反应 (PCR)及聚丙烯酰胺凝胶电泳等技术检测 SCA7基因内 CAG三核苷酸重复序列的突变 ,并利用 ABI373测序仪对异常等位基因片段进行 DNA测序。结果　 2 4例 SCA患者的 SCA7等位基因 CAG重复数目为 9～ 18。正常人 SCA7等位基因 CAG重复数目为 9～ 19。检出 1例散发患者为 SCA7,经基因测序证实 ,其异常等位基因的 CAG重复数目为 6 3。结论　 CAG过度扩增是 SCA7的致病原因 ,利用基因突变分析可进行基因诊断 ,提供症状前诊断及遗传咨询的依据 ,为基因分型奠定基础。Objective To study the gene mutation and clinical characteristic of hereditary spinocerebellar ataxia type 7 (SCA7).Methods The SCA7 (CAG) trinucleotide repeat mutations were detected by polymerase chain reaction(PCR) and polyacrylamide gel electrophoresis technique in 24 patients with autosomal dominant SCA from 15 families, 20 sporadic SCA patients and 41 normal persons from the same family and 30 healthy persons from different family,the abnormal allele fragments were sequenced by ABI 373 DNA sequencing machine.Results 24 patients with SCA had CAG repeat numbers of SCA 7 allele from 9~18.Normal alleles of SCA 7 had CAG repeat number from 9 to 19. One sporadic SCA patient had one abnormal SCA 7 allele with the CAG repeat expanded to 63 repeats, being confirmed by DNA sequencing.Conclusion CAG expansions were pathogenic cause of SCA 7. The technique of gene mutation detection could provide an effective way for the prediction of asymptomatic and genetic counseling,which was a basis for gene typing.

关 键 词：脊髓小脑性共济失调 橄榄桥脑小脑萎缩 视网膜色素变性 三核苷酸重复 

分 类 号：R742.82[医药卫生—神经病学与精神病学] R596.1[医药卫生—临床医学]